A217167 - OEIS

%I #14 Oct 02 2012 14:27:09

%S 5,7,5,8,7,1,4,4,0,1,4,4,4,2,5,3,8,9,0,4,2,8,3,4,1,4,7,1,0,8,3,3,1,2,

%T 6,7,4,4,0,1,8,8,4,1,1,2,1,1,0,7,1,8,1,5,4,5,3,1,0,2,4,0,4,2,6,4,4,2,

%U 0,1,0,3,2,7,7,7,5,0,0,4,5,8,1,2,0,3,8

%N a(n) is the first digit (from the left) to appear two times in succession in the decimal representation of n^A217157(n).

%C Note that 109^2 = 11881. So by looking at the digits from the left, we have a(109) = 1.

%H V. Raman, <a href="/A217167/b217167.txt">Table of n, a(n) for n = 2..10000</a>

%t Table[k = 1; While[d = IntegerDigits[n^k]; ! MemberQ[df = Differences[d], 0], k++]; d[[Position[df, 0][[1, 1]]]], {n, 2, 100}] (* _T. D. Noe_, Oct 02 2012 *)

%Y Cf. A217157.

%Y Cf. A215732, A215236.

%Y Cf. A215733, A215734, A215735, A215736, A215737.

%K nonn,base

%O 2,1

%A _V. Raman_, Sep 27 2012